Method for controlling an air conditioner

ABSTRACT

A method for controlling an air conditioner. The method for controlling an air conditioner may include determining time information for determining an execution time of a low-noise operation and performing the low-noise operation according to the determined time information. The performing of the low-noise operation may include limiting a maximum value of an operation frequency of a compressor; and reducing an amount of refrigerant introduced into an indoor unit or device.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims priority under 35 U.S.C. 119 and 35 U.S.C. 365 to Korean Patent Application No. 10-2014-0048086, filed in Korea on Apr. 22, 2014, which is hereby incorporated by reference in its entirety.

BACKGROUND

1. Field

A method for controlling an air conditioner, which is capable of reducing noise at night, is disclosed herein.

2. Background

Air conditioners are home appliances that maintain indoor air in a most proper state according to abuse and purpose. Such an air conditioner may include an indoor unit or device installed in an indoor space, and an outdoor unit or device that supplies a refrigerant into the indoor unit. At least one indoor unit may be connected to the outdoor unit, and components, such as a compressor and a heat exchanger, may be provided in the outdoor unit.

The air conditioner may perform cooling or heating operations according to a flow of the refrigerant supplied into the indoor unit. In detail, when the air conditioner performs the cooling operation, the refrigerant compressed in the compressor of the outdoor unit may be condensed while passing through the outdoor heat exchanger. When the condensed refrigerant is supplied into the indoor unit, the refrigerant may be decompressed in an indoor expansion device and be evaporated in an indoor heat exchanger. Thus, a temperature of air introduced into the indoor unit may be reduced by the evaporation of the refrigerant. Also, while an indoor fan rotates, the cooled air may be discharged into an indoor space.

When the heating operation is performed in the air conditioner, a flow of the refrigerant may be as follows. When a high-temperature, high-pressure gas refrigerant is supplied from the compressor of the outdoor unit to the indoor unit, the refrigerant may be condensed while passing through the indoor heat exchanger. Heat released by condensation of the refrigerant may raise a temperature of the air introduced into the indoor unit. Also, while the indoor fan rotates, the heated air may be discharged into the indoor space.

The air conditioner having the above-described functions is increasingly being used in the market place, and thus, increases in function thereof are required. In particular, as a user's sensitivity with respect to noise increases, noise reduction technologies are an important part in the development of air conditioners.

A main cause of noise in the air conditioner may be noise of the compressor and fan of the outdoor unit and air-blowing and refrigerant noise of the indoor unit. Korean Patent Publication No. 10-2000-0010414 (hereinafter, referred to as a “related art”) discloses a technology for reducing air-blowing noise, which is one cause of noise.

In detail, the related art may have a feature in which, when a low-noise operation mode key signal is input while the air conditioner operates, a wind angle and amount in a wind direction adjustment part are adjusted to a preset wind angle and amount to correspond to the low-noise operation mode. In the related art, the air-blowing noise of the air discharged from the indoor unit may be reduced, but flow noise of the refrigerant may not be reduced. In particular, when the air conditioner operates with low noise at night, the air-blowing noise of the refrigerant may be more sensitively felt or heard. Also, in the related art, a process for directly inputting the low-noise operation mode by a user to reduce the air-blowing noise has to be performed. However, the input process may cause or result in user inconvenience.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments will be described in detail with reference to the following drawings in which like reference numerals refer to like elements, and wherein:

FIGS. 1A-1B are schematic views of an air conditioner according to an embodiment;

FIG. 2 is a system view of the air conditioner according to an embodiment;

FIG. 3 is a flowchart of a process of setting time determination logic for performing a low-noise operation of the air conditioner according to an embodiment;

FIGS. 4A-4B are graphs of a time-varying temperature distribution;

FIG. 5 is a flowchart of a process of controlling the air conditioner when a low-noise cooling operation depending on time determination logic is performed according to an embodiment; and

FIG. 6 is a flowchart of a process of controlling the air conditioner when a low-noise heating operation depending on time determination logic is performed according to an embodiment.

DETAILED DESCRIPTION

Hereinafter, embodiments will be described with reference to the accompanying drawings. The embodiments may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein; rather, alternate embodiments falling within the spirit and scope will fully convey the concept to those skilled in the art.

FIGS. 1A-1B are schematic views of an air conditioner according to an embodiment. FIG. 2 is a system view of the air conditioner according to an embodiment.

Referring to FIG. 1, an air conditioner according to an embodiment may include an indoor unit or device 200 that discharges conditioned air into an indoor space, and an outdoor unit or device 100 connected to the indoor unit 200 and disposed in an outdoor space. The outdoor unit 100 and the indoor unit 200 may be connected to each other through or by a refrigerant tube. As a refrigerant cycle operates, heated or cooled air may be discharged into the indoor space from the indoor unit 200. A plurality of the indoor unit 200 may be provided, and the plurality of indoor units 200 may be connected to the outdoor unit 100.

For example, as illustrated in FIG. 1A, the air conditioner may include one indoor unit 200 and one outdoor unit 100 with a one-to-one correspondence. On the other hand, as illustrated in FIG. 1B, the air conditioner may include a plurality of indoor units 200 and at least one outdoor unit 100 connected to the plurality of indoor units 200. The plurality of indoor unit 200 and the outdoor unit 100 may be connected to each other through or by a refrigerant tube.

The indoor unit 200 may include a discharge hole to discharge air heat-exchanged through an indoor heat exchanger 210. A wind direction adjustment part or portion to open or close the discharge hole and control a direction of the discharged air may be disposed in the discharge hole.

The indoor unit 200 may include a vane to adjust an amount of air discharged from the discharge hole. For example, the vane may be movably provided to adjust an opening degree of the discharge hole. The vane may move to adjust a discharge direction of air.

The indoor unit 200 may further include a display part or display to display operation information of the indoor unit 200, and an input part or input to input a set command. When a user inputs an operation starting command of the air conditioner through the input unit, the air conditioner may operate in a cooling mode or a heating mode in response to the input command.

In detail, referring to FIG. 2, the outdoor unit 100 may include an outdoor heat exchanger 110, in which indoor air and the refrigerant may be heat-exchanged with each other, and an outdoor blower 120 to blow the indoor air to the outdoor heat exchanger 110. The outdoor blower 120 may include an outdoor fan 121, and an outdoor fan motor 122.

The outdoor unit 100 may further include an accumulator 300 that separates a gas refrigerant from an evaporated refrigerant, and a compressor 150 that suctions and compresses the gas refrigerant separated in the accumulator 300. The outdoor unit 100 may also include a 4-way valve 130 that converts a flow of the refrigerant compressed in the compressor 150. When the air conditioner performs a cooling operation, the 4-way valve 130 may guide the refrigerant discharged from the compressor 150 to the outdoor heat exchanger 110. On the other hand, when the air conditioner performs a heating operation, the 4-way valve may guide the refrigerant discharged from the compressor 150 to the indoor heat exchanger 210.

A main expansion device 115 may be disposed on or at one side of the outdoor heat exchanger 110. The main expansion device 115 may include an electronic expansion valve (EEV). When the air conditioner performs the heating operation, the refrigerant decompressed in the main expansion device 115 may be evaporated in the outdoor heat exchanger 110.

The outdoor unit 100 may further include a supercooling heat exchanger 160 disposed on or at an outlet-side of the outdoor heat exchanger 110. For example, when the air conditioner performs the cooling operation, the refrigerant passing through the outdoor heat exchanger 110 may be introduced into the supercooling heat exchanger 160.

The supercooling heat exchanger 160 may be referred to as an “intermediate heat exchanger”, in which a first refrigerant circulating into a refrigerant system and a portion (a second refrigerant) of the refrigerant may be branched and then heat-exchanged with each other. The first refrigerant may be a “main refrigerant” circulating in the refrigerant system, and the second refrigerant may be a “branched refrigerant” introduced into the compressor 150.

The outdoor unit 100 may additionally further include a supercooling passage 161, into which the second refrigerant may be branched, and a supercooling expansion device 163 disposed in the supercooling passage 161 to decompress the second refrigerant. An amount of refrigerant flowing through the supercooling passage 161 may vary according to an opening degree of the supercooling expansion device 163. For example, the supercooling expansion device 163 may include an electronic expansion valve (EEV).

A plurality of temperature sensors 164 and 165 may be provided in the supercooling passage 161. The plurality of temperature sensors 164 and 165 may include a first supercooling sensor 164 that detects a refrigerant temperature before the refrigerant is introduced into the supercooling heat exchanger 160, and a second supercooling sensor 165 that detects a refrigerant temperature after the refrigerant passes through the supercooling heat exchanger 160. While the first and second refrigerants are heat-exchanged with each other in the supercooling heat exchanger 160, the first refrigerant may be excessively condensed or supercooled, and the second refrigerant may be heated or overheated.

A “superheating degree” of the second refrigerant may be recognized based on a temperature value of the refrigerant detected by each of the first and second supercooling sensors 164 and 165. For example, the temperature value detected by the first supercooling sensor 164, which is subtracted from the temperature value detected by the second supercooling sensor 165, may be recognized as the “superheating degree”.

The superheating degree of the second refrigerant may vary according to the opening degree of the supercooling expansion device 163. For example, when the opening degree of the supercooling expansion device 163 decreases to reduce an amount of refrigerant flowing through the supercooling passage 161, the superheating degree of the second refrigerant may increase. On the other hand, when the opening degree of the supercooling expansion device 163 increases to increase an amount of refrigerant flowing through the supercooling passage 161, the superheating degree of the second refrigerant may decrease.

The indoor unit 200 may include the indoor heat exchanger 210, in which the indoor air and the refrigerant may be heat-exchanged with each other, and an indoor blower 220 to blow the indoor air to the indoor heat exchanger 210. The indoor blower 220 may include an indoor fan 221, and an indoor fan motor 222.

The indoor unit 200 may further include an indoor expansion device 215 disposed on or at one side of the indoor heat exchanger 210. The indoor expansion device 215 may include an electronic expansion valve (EEV). When the air conditioner performs the cooling operation, the refrigerant decompressed in the indoor expansion device 215 may be evaporated in the indoor heat exchanger 210.

A plurality of temperature sensors 211 and 212 may be disposed on or at inlet and outlet-sides of the indoor heat exchanger 210, respectively. The plurality of temperature sensors 211 and 212 may include a first temperature sensor 211, and a second temperature sensor 212. A superheating degree or supercooling degree of a refrigerant cycle may be determined by values detected in or by the first and second temperature sensors 211 and 212.

For example, when the air conditioner performs the cooling operation, a difference between the values detected in the first and second temperature sensors 211 and 212 may represent the superheating degree. When the opening degree of the indoor expansion device 215 decreases to reduce an amount of refrigerant introduced into the indoor unit 200, the superheating degree may increase. On the other hand, when the air conditioner performs the heating operation, a difference between the values detected in the first and second temperature sensors 211 and 212 may represent the supercooling degree. When the opening degree of the indoor expansion device 215 decreases to reduce an amount of refrigerant introduced into the indoor unit 200, the supercooling degree may increase.

Hereinafter, a method for controlling a night low-noise operation in the air conditioner including the above-described components will be described hereinbelow.

FIG. 3 is a flowchart of a process of setting time determination logic for performing a low-noise operation of the air conditioner according to an embodiment. FIGS. 4A-4B are graphs of a time-varying temperature distribution.

The air conditioner according to an embodiment may perform a night low-noise operation depending on time determination logic. In detail, the method for controlling the air conditioner may include a time information determination process of determining an execution time of a low-noise operation and a process of performing the low-noise operation depending on the determined time information.

The time information determination process may include a process of determining a reference time through a set operation process, and a process of determining an execution time range of the low-noise operation based on the determined reference time. The process of determining the reference time may include a process of performing a plurality of set operation processes. For example, the plurality of set operation processes may include operation processes which are set two times, that is, a primary operation process and a secondary operation process.

The process of performing the low-noise operation may include an operation process for reducing refrigerant noise or air-blowing noise generated in the outdoor unit 100 and the indoor unit 200 within a range of an execution time of the determined low-noise operation. In detail, with reference to FIG. 3, when the air conditioner is turned on, in operation as step S11, the primary operation process may be performed, in step or operation S12. When the primary operation process is performed, a state in which power is supplied to the air conditioner for a preset or predetermined time (period) may be maintained to measure a temperature of external air. For example, the preset time may be about one day (24 hours).

Also, distribution of an external air temperature measured during the primary operation process may be datarized (primary operation data), and a time or time period that represents a highest temperature in the measured external air temperature distribution may be set to a reference time (reference time period). That is, as illustrated in FIG. 4A, during the primary operation process, the temperature distribution measured for 24 hours may be datarized, and a time period that represents a highest temperature distribution of the measured temperature distribution may be set to a reference time period. For example, in operation or step S13, a time period between 13 o'clock and 14 o'clock may be set to the reference time period.

When the primary operation process is completed, a secondary operation process may be performed, in operation or step 14. The secondary operation process may include a process of re-measuring the external air temperature to datarize and store the measured external air distribution (secondary operation data). In operation or step S15, a process of comparing the reference time set using the secondary operation data to the reference time set in operation S13 may be performed. If a difference between the secondary operation data and information with respect to the set reference time does not occur, the reference time set in operation S13 may be determined as a final reference time, in operation or step S16.

On the other hand, if the difference between the secondary operation data and the information with respect to the set reference time occurs, a mean value of the primary operation data and the secondary operation data may be reset to a reference time. Also, in operation or step S17, the reset reference time may be determined as a final reference time. The determined final reference time may be used as information for determining the low-noise operation execution time. In detail, a prior time period (a) and a posterior time period (b) may be determined with reference to the determined final reference time. For example, each of the prior time period (a) and the posterior time period (b) may be previously set to a predetermined value.

For example, if the final reference time is determined to be 13 o'clock to 14 o'clock, as illustrated in FIG. 4A, a time period between a time (6 o'clock) prior to 7 o'clock and a time (20 o'clock) posterior to 7 o'clock with respect to 13 o'clock, which is a start time of the final reference time period, may be determined as a low-noise operation exclusion time, as illustrated in FIG. 4B. Also, a remaining time period, that is, a time period between 20 o'clock and 6 o'clock may be determined as the low-noise operation execution time period.

As described above, when the low-noise operation execution time period is determined, an operation of the air conditioner may be performed according to the determined low-noise operation execution time period, in operation or step S18. The low-noise operation may be referred to as an operation for reducing the refrigerant noise and air-blowing noise of the outdoor unit 100 and the indoor unit 200. In operation or step S19, the low-noise operation may be performed until an OFF command of the air conditioner is input.

The low-noise operation may be performed in all of the cooling and heating modes when the cooling and heating modes of the air conditioner operate. Hereinafter, a method for controlling operations of cooling and heating modes of an air conditioner according to an embodiment will be described with reference to the accompanying drawings.

FIG. 5 is a flowchart oaf process of controlling the air conditioner when a low-noise cooling operation depending on time determination logic is performed according to an embodiment. Referring to FIG. 5, in operation or step S21, the cooling operation of the air conditioner starts, and a low-noise operation mode is input. Before the cooling operation according to an embodiment is performed, the reference time and the low-noise operation execution time period according to the control method of FIG. 3 may be previously determined and stored in the air conditioner. That is, the control method of FIG. 5 may be referred to as an embodiment of the performing of the cooling operation of the air conditioner in operation S18 of FIG. 3.

Whether an operation time of the air conditioner is included in the set low-noise operation execution time period may be recognized. In operation or step S22, the operation time of the air conditioner may be a corresponding reservation time when the present time or operation reservation command is input.

When the operation time of the air conditioner is not included in the set low-noise operation execution time period, each of the indoor unit 100 and the outdoor unit 200 may perform a normal operation. In operation or step S24, the normal operation may be referred to as an operation of the air conditioner in which the low-noise operation mode is not performed.

On the other hand, in operation or step S23, when the operation time of the air conditioner is included in the set low-noise operation execution time period, a low-noise cooling operation may be performed. When the low-noise cooling operation is performed, a control of reducing the refrigerant noise and air-blowing noise of the indoor unit 100 and the outdoor unit 200 may be performed, in operation or step S25. In detail, to reduce the noise of the outdoor unit 100, a rotational rate of the outdoor blower 120 may be controlled to be less than a preset or predetermined rotational rate. For example, the preset or predetermined rotational rate may be about 70% of a maximum rotational rate.

Also, a frequency of the compressor 150 may be controlled to be less than a preset or predetermined frequency. For example, the preset or predetermined frequency may be about 70% of a maximum frequency. As described above, when the frequency of the compressor 150 is controlled, the outdoor unit 100 may operate to a level of about 50% or less of the maximum load required for performing the cooling operation.

To reduce the refrigerant noise generated in the indoor unit 200, the opening degree of the indoor expansion device 215 may be adjusted, in operation or step S27. In detail, to increase a target superheating degree of a refrigeration cycle, the opening degree of the indoor expansion device 215 may decrease. When the opening degree of the indoor expansion device 215 decreases, a temperature difference between an inlet and outlet of the indoor heat exchanger 210 may increase. Also, the set temperature may be about 2° C. When the target superheating degree increases, an amount of refrigerant introduced into the indoor unit 200 may be reduced.

Also, to reduce the noise generated in the indoor blower 220, an amount of wind of the indoor blower 220 may be reduced. For example, the amount of wind of the indoor blower 200 may be controlled in stages. Thus, the amount of wind of the indoor blower 220 may be reduced by one stage (e.g., strong->middle or medium) to reduce the air-blowing noise, in operation or step S26.

When the target superheating degree increases, an amount of refrigerant passing through the indoor heat exchanger 210 may decrease to allow a low-pressure of the refrigerant cycle to increase. Thus, a situation in which the target low-pressure is not satisfied may occur. In particular, in a case of a tropical night at which external air has a high temperature, the target low-pressure may not be satisfied, reducing cooling performance.

Thus, in this embodiment, while the low-noise cooling operation is performed, if the target low-pressure is not satisfied, in operation or step S27, a cooling supplementation operation process for supplementing the dissatisfaction of the target low-pressure may be performed. The cooling supplementation operation process may be referred to as an operation process for checking whether the target low-pressure is satisfied while an operation of the indoor unit 100 varies in stages.

In detail, the cooling supplementation operation process may include a primary supplementation operation process (operation or step S28), in which a rotational rate of the outdoor blower 120 varies, a secondary supplementation operation process (operation or step S30), in which an operation frequency of the compressor 150 varies, and a tertiary supplementation operation process (operation or step S32), in which the outdoor blower 120 and the compressor 150 normally operate. In the primary supplementation operation process, the rotational rate of the outdoor blower 120 which may be controlled to about 70% or less of the maximum rotational rate, in operation S24, may increase up to about 80% of the maximum rotational rate. In operation or step S29, after the primary supplementation operation process is performed, whether the target low-pressure may be satisfied is checked.

If the target low-pressure is not satisfied after the primary supplementation operation process is performed, the secondary supplementation operation process may be performed. In the secondary supplementation operation process, the operation frequency of the compressor 150, which may be controlled to about 50% or less of the maximum frequency, in operation S24, may increase up to about 70% of the maximum frequency, and then, whether the target low-pressure is satisfied may be checked, in operation or step S31.

If the target low-pressure is not satisfied after the secondary supplementation operation process is performed, the tertiary supplementation operation process may be performed. In the tertiary supplementation operation process, the outdoor blower 120 and the compressor 150 may be controlled so that the outdoor blower 120 and the compressor 150 normally operate adequate for the preset or predetermined temperature to exert the cooling performance required by the user.

The normal operation may represent a state in which the outdoor blower 120 and the compressor 150 operate based on the preset temperature and indoor temperature without limiting the operations of the outdoor blower 120 and the compressor 150. Thus, in operation or step S32, the rotational rate of the outdoor blower 120 may be controlled to operate up to about 100% of the maximum rotational rate, and the frequency of the compressor 150 may be controlled to operate up to about 100% of the maximum frequency. In operation or step S33, the control method may be performed until the OFF command is input into the air conditioner.

FIG. 6 is a flowchart of a process of controlling the air conditioner when a low-noise heating operation depending on time determination logic is performed according to an embodiment. Referring to FIG. 6, in operation or step S41, the heating operation of the air conditioner may start, and a low-noise operation mode may be input. Before the cooling operation according to an embodiment is performed, the reference time and the low-noise operation execution time period according to the control method of FIG. 3 may be previously determined and stored in the air conditioner.

That is, the control method of FIG. 6 may be referred toes an embodiment of the performing of the heating operation of the air conditioner in operation S18 of FIG. 3. Whether an operation time of the air conditioner is included in the set low-noise operation execution time period may be recognized. In operation or step S42, the operation time of the air conditioner may be a corresponding reservation time when the present time or operation reservation command is inputted.

In operation or step S44, when the operation time of the air conditioner is not include in the set low-noise operation execution time period, each of the indoor unit 100 and the outdoor unit 200 may perform a normal operation. On the other hand, in operation or step S43, when the operation time of the air conditioner is included in the set low-noise operation execution time period, a low-noise heating operation may be performed.

When the low-noise heating operation is performed, a control of reducing the refrigerant noise and air-blowing noise of the indoor unit 100 and the outdoor unit 200 may be performed. In detail, a frequency of the compressor 150 may be controlled to be less than a preset or predetermined frequency. For example, the preset or predetermined frequency may be about 70% of a maximum frequency.

Also, as the maximum rotational number of the fan of the outdoor blower 120 is not limited, a defrosting operation may be smoothly performed, in operation or step S45. Also, when the low-noise heating operation is performed, an opening degree of the supercooling expansion device 163 may be adjusted to reduce the refrigerant noise.

In detail, to increase a target supercooling degree of a refrigeration cycle, an opening degree of the indoor expansion device 215 may be reduced. When the opening degree of the indoor expansion device 215 decreases, a temperature difference between an inlet and outlet of the indoor heat exchanger 210 may increase. The set temperature may be about 3° C. When the target supercooling degree increases, an amount of refrigerant introduced into the indoor unit 200 may be reduced.

Also, to reduce the noise generated in the indoor blower 220, an amount of wind of the indoor blower 220 may be reduced. For example, the amount of wind of the indoor blower 200 may be controlled in stages. Thus, the amount of wind of the indoor blower 220 may be reduced by one stage (for example, strong->middle or medium) to reduce the air-blowing noise, in operation or step S46.

When the target superheating degree increases, an amount of refrigerant passing through the indoor heat exchanger 210 may decrease to allow a high-pressure of the refrigerant cycle to decrease. Thus, a situation in which the target low-pressure is not satisfied may occur. Thus, the target high-pressure may not be satisfied to deteriorate heating performance.

Thus, in this embodiment, while the low-noise heating operation is performed, if the target high-pressure is not satisfied, in operation or step S47, a heating supplementation operation process for supplementing the dissatisfaction of the target high-pressure may be performed. The heating supplementation operation process may represent a state in which the compressor 150 normally operates without limiting the operation frequency of the compressor 150.

That is, when the low-noise heating operation is performed, if the target high-pressure of the refrigeration cycle is not satisfied, the compressor 150 may normally operate until the target high-pressure has been reached, in operations or steps S48 and S49. Thus, the heating performance may be improved by the above-described heating supplementation operation.

According to embodiments, even though a separate operation time is not set by the user, the night low-noise operation depending on time determination logic may be controlled to improve convenience in use and reduce power consumption due to the low-noise operation. Also, when the night low-noise operation is controlled, reduction of the refrigerant noise within the indoor unit, as well as noise reduction due to control of the fan and compressor of the outdoor unit may be realized to more effectively reduce the noise at night.

Further, when a target high-low pressure, which is required for the night low-noise operation, is not satisfied, supplementation logic for supplementing the dissatisfied high-low pressure may be performed. Thus, the air conditioner may be improved in performance to improve consumer's product satisfaction.

Embodiments provide a method for controlling an air conditioner in which a low-noise operation is enabled.

Embodiments disclosed herein provide a method for controlling an air conditioner that may include determining time information for determining an execution time of a low-noise operation, and performing the low-noise operation according to the determined time information. The performing of the low-noise operation may include limiting a maximum value of an operation frequency of a compressor, and reducing an amount of refrigerant introduced into an indoor unit or device.

The performing of the low-noise operation may include reducing an amount of wind of an indoor blower. The performing of the low-noise operation may further include limiting a maximum value of a rotational rate of an outdoor blower.

The maximum value of the rotational rate of the outdoor blower may be limited to about 70% or less of the maximum rotational rate of the outdoor blower. The maximum value of the operation frequency of the compressor may be limited to about 50% or less of the maximum frequency of the compressor when the air conditioner perform a cooling operation and be limited to about 70% or less of the maximum frequency of the compressor when the air conditioner performs a heating operation.

The reducing of the amount of refrigerant introduced into the indoor unit may include increasing a target superheating degree and a target supercooling degree of the indoor unit. The increasing of the target superheating degree and the target supercooling degree of the indoor unit may include reducing an opening degree of an expansion device provided in the indoor unit.

The determining the time information for determining the execution time of the low-noise operation may include determining a reference time through a set operation process, and determining a range of the execution time of the low-noise operation on the basis of the determined reference time.

The set operation process may include measuring an external air temperature at a set cycle; datarizing distribution of the external air temperature to store the datarized distribution; and setting a time period corresponding to the highest temperature in the distribution of the measured external air temperature as a reference time period. The set operation process may include primary and secondary operation processes, and the method may further include comparing a reference time period set in the primary operation process to a reference time period set in the secondary operation process. When a difference between the reference time period set in the primary operation process and the reference time period set in the secondary operation process occurs, the reference time period may be determined using a mean value of data of the primary operation process and data of the secondary operation process.

The method may further include recognizing whether a target pressure of a refrigeration cycle is satisfied while the low-noise operation is performed, and performing a supplementation operation if the target pressure is not satisfied. When a target low-pressure is not satisfied while the air conditioner performs a cooling operation, the performing of the supplementation operation may include performing a primary supplementation operation, in which a rotational rate of the outdoor blower may vary.

The performing of the supplementation operation may further include performing a secondary supplementation operation in which an operation frequency of the compressor may vary if the target low-pressure is not satisfied after the primary supplementation operation is performed. The performing of the supplementation operation may further include performing a tertiary supplementation operation in which the outdoor blower and the compressor may normally operate without limiting the rotational rate of the outdoor blower and the frequency of the compressor if the target low-pressure is not satisfied after the secondary supplementation operation is performed. When a target high-pressure is not satisfied while the air conditioner performs a heating operation, the performing of the supplementation operation may include allowing the compressor to normally operate without limiting a frequency of the compressor.

The details of one or more embodiments are set forth in the accompanying drawings and the description. Other features will be apparent from the description and drawings, and from the claims.

Although embodiments have been described with reference to a number of illustrative embodiments thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles. More particularly, various variations and modifications are possible in the component parts and/or arrangements of the subject combination arrangement within the scope, the drawings and the appended claims. In addition to variations and modifications in the component parts and/or arrangements, alternative uses will also be apparent to those skilled in the art.

Any reference in this specification to “one embodiment,” “an embodiment,” “example embodiment,” etc., means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with any embodiment, it is submitted that it is within the purview of one skilled in the art to effect such feature, structure, or characteristic in connection with other ones of the embodiments.

Although embodiments have been described with reference to a number of illustrative embodiments thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this disclosure. More particularly, various variations and modifications are possible in the component parts and/or arrangements of the subject combination arrangement within the scope of the disclosure, the drawings and the appended claims. In addition to variations and modifications in the component parts and/or arrangements, alternative uses will also be apparent to those skilled in the art. 

What is claimed is:
 1. A method for controlling an air conditioner, the method comprising: determining time information for determining an execution time of a low-noise operation; and performing the low-noise operation according to the determined time information, wherein the performing of the low-noise operation comprises: limiting a maximum value of an operation frequency of a compressor; and reducing an amount of refrigerant introduced into an indoor device.
 2. The method according to claim 1, wherein the performing of the low-noise operation further comprises reducing an amount of wind of an indoor blower.
 3. The method according to claim 1, wherein the performing of the low-noise operation further comprises limiting a maximum value of a rotational rate of an outdoor blower.
 4. The method according to claim 3, wherein the maximum value of the rotational rate of the outdoor blower is limited to about 70% or less of a maximum rotational rate of the outdoor blower.
 5. The method according to claim 3, further comprising: recognizing whether a target pressure of a refrigeration cycle is satisfied while the low-noise operation is performed; and performing a supplementation operation if the target pressure is not satisfied.
 6. The method according to claim 5, wherein, when a target low-pressure is not satisfied while the air conditioner performs a cooling operation, the performing of the supplementation operation comprises performing a primary supplementation operation in which a rotational rate of the outdoor blower varies.
 7. The method according to claim 16, wherein the performing of the supplementation operation further comprises performing a secondary supplementation operation in which an operation frequency of the compressor varies if the target low-pressure is not satisfied after the primary supplementation operation is performed.
 8. The method according to claim 7, wherein the performing of the supplementation operation further comprises performing a tertiary supplementation operation in which the outdoor blower and the compressor normally operate without limiting the rotational rate of the outdoor blower and the frequency of the compressor if the target low-pressure is not satisfied after the secondary supplementation operation is performed.
 9. The method according to claim 5, wherein, when a target high-pressure is not satisfied while the air conditioner performs a heating operation, the performing of the supplementation operation comprises allowing the compressor to normally operate without limiting a frequency of the compressor.
 10. The method according to claim 1, wherein the maximum value of the operation frequency of the compressor is limited to about 50% or less of the maximum frequency of the compressor when the air conditioner performs a cooling operation and is limited to about 70% or less of the maximum frequency of the compressor when the air conditioner performs a heating operation.
 11. The method according to claim 1, wherein the reducing of the amount of refrigerant introduced into the indoor device comprises increasing a target superheating degree and a target supercooling degree of the indoor device.
 12. The method according to claim 11, wherein the increasing of the target superheating degree and the target supercooling degree of the indoor device comprises reducing an opening degree of an expansion device provided in the indoor device.
 13. The method according to claim 1, wherein the determining the time information for determining the execution time of the low-noise operation comprises: determining a reference time through a predetermined operation process; and determining a range of the execution time of the low-noise operation on the basis of the determined reference time.
 14. The method according to claim 13, wherein the predetermined operation process comprises: measuring an external air temperature at a predetermined cycle; datarizing distribution of the external air temperature to store the datarized distribution; and setting a time period corresponding to a highest temperature in the distribution of the measured external air temperature as a reference time period.
 15. The method according to claim 13, wherein the predetermined operation process comprises primary and secondary operation processes, and wherein the method further comprises comparing a reference time period set in the primary operation process to a reference time period set in the secondary operation process.
 16. The method according to claim 15, wherein, when a difference between the reference time period set in the primary operation process and the reference time period set in the secondary operation process occurs, the reference time period is determined by using a mean value of data of the primary operation process and data of the secondary operation process.
 17. A method for controlling an air conditioner, the method comprising: determining time information for determining an execution time of a low-noise operation; and performing the low-noise operation according to the determined time information, wherein the performing of the low-noise operation comprises: limiting of an operation frequency of a compressor; and reducing an amount of refrigerant introduced into an indoor device, and wherein the determining the time information for determining the execution time of the low-noise operation comprises: determining a reference time through a predetermined operation process; and determining a range of the execution time of the low-noise operation on the basis of the determined reference time.
 18. The method according to claim 17, wherein the predetermined operation process comprises: measuring an external air temperature at a predetermined cycle; datarizing distribution of the external air temperature to store the datarized distribution; and setting a time period corresponding to a highest temperature in the distribution of the measured external air temperature as a reference time period.
 19. The method according to claim 17, wherein the predetermined operation process comprises primary and secondary operation processes, and wherein the method further comprises comparing a reference time period set in the primary operation process to a reference time period set in the secondary operation process.
 20. The method according to claim 19, wherein, when a difference between the reference time period set in the primary operation process and the reference time period set in the secondary operation process occurs, the reference time period is determined by using a mean value of data of the primary operation process and data of the secondary operation process.
 21. A method for controlling an air conditioner, the method comprising: determining time information for determining an execution time of a low-noise operation; and performing the low-noise operation according to the determined time information, wherein the performing of the low-noise operation comprises: limiting of an operation frequency of a compressor; and reducing an amount of refrigerant introduced into an indoor device, and wherein the reducing of the amount of refrigerant introduced into the indoor device comprises increasing a target superheating degree and a target supercooling degree of the indoor device.
 22. The method according to claim 21, wherein the increasing of the target superheating degree and the target supercooling degree of the indoor device comprises reducing an opening degree of an expansion device provided in the indoor device. 